When he was a teenager, Brian Paskoff, of Holtsville, frequented Beez’s Trading Post in Ronkonkoma. He regularly bought packs of Magic: the Gathering cards in the mid '90s. One day, he pulled an Underground Sea card from the 1994 Revised set. Today that card is the highlight of his collection, valued at $600.

"I have all my cards from when I was a kid," says Paskoff, 41, who now continues his hobby by shopping at Brothers Grim Games & Collectibles in Selden. "I like to look at the artwork and meet new people in the Magic community."

Trading cards is big business. In 2023, rapper Post Malone paid $2.64 million for a "The One Ring" card from the Magic: the Gathering 2023 Lord of the Rings: Tales of Middle Earth set, graded 9 in mint condition. That sale was topped last year when a Black Lotus card from the Magic: the Gathering 1993 Alpha limited edition set, graded 10, was sold for $3 million.

"A card is worth nothing until someone buys it. It’s all based on whatever the market dictates," says Trent Humphries of Tolaria East, Inc., a Magic: the Gathering card seller from Miller Place. "Every card is worth as much as the buyer is willing to put on the table."

A big turning point in the card collecting world came during the pandemic when the market increased by more than 150%.

"People were looking to keep themselves busy while stuck inside the house. They’d go through their attic or basement to find their old card collection and look through it again," says Richard McWilliams, owner of Blast from the Past in Bay Shore. "Everyone started ordering online like crazy. As a result, the industry saw a tremendous boom. It was humongous."

Cards of various types, baseball, Pokémon, Magic: the Gathering and Yu-Gi-Oh!, have become hot commodities. But not just any cards. The value of a card depends on several elements.

"A lot of different factors come into play," says head buyer Ryan Callahan, of Rip N Ship in Deer Park. "You must analyze the condition of the card, how frequently it sells, what it sells for, how much it fluctuates in the market and the popularity of the card."

Here are four types of high value cards plus the Long Islanders who collect and sell them.

Over at Grand Slam Collectibles in Bellport general manager Anthony DeLillo is keeping things moving. The 7,000-square-foot store is open seven days a week buying and selling baseball cards (and other types).

"We are looking for rookie cards, autographs, numbered cards, vintage stuff from the '50s, '60s and '70s," says DeLillo. "Some are only numbered 1 to 10 meaning there’s only 10 in the whole world. The lower that number is, the more valuable the card is because it is more exclusive."

Currently, there’s an autographed Aaron Judge Yankees rookie card, PSA graded 10 from 2017, for sale at $1,500.

DeLillo also has old cards like a 1953 Jackie Robinson from the Brooklyn Dodgers, graded 2, for $450 as well as a 1958 Willie Mays from the San Francisco Giants, graded 3, for $200.

"That vintage stuff is the most liquid gold you can find," says DeLillo. "But the condition is usually not so good."

Alex Caviris, of Plainview, has been collecting Magic: the Gathering cards since they came out in 1993. Today his collection consists of several hundred thousand cards and is worth $165,000.

"I was lucky enough to be brought in at ground level," says Caviris, 43. "As a nerdy kid, I was drawn to the attention-grabbing art with cool names."

His most precious card is his Mox Sapphire from the 1993 Unlimited Edition, in slightly played condition, valued at $3,000.

Meanwhile Humphries is rocking a commander 100-card deck he compiled over a six-year period worth $30,000 based on one creature, Sisay, Weatherlight Captain.

"This is all cardboard stocks and bonds," says Humphries, 28, who sells Magic cards on Facebook and at local card shows. "You have to be able to figure out which card is going to crash, which one is going to spike and make your move."

Pokémon has been a part of Saverio Lombardi’s life since age 7. The Bay Shore resident has a few thousand Pokémon cards in his collection, which is worth $25,000. His top card? A Pokémon Blastoise from the first edition base set, PSA graded 10, from 1999. He bought it in 2013 for $1,000. Today the card is worth $20,000.

"I basically collect the cards that I like," says Lombardi, 34. "The hobby provides a sense of fulfillment and it brings people together. We all have a shared passion."

Back in 1999, Steve Hesse, of Port Jefferson Station, was a Pokémon card collector but fell off as he got older. However, his interest was renewed when he got his 3-year-old son Carter into the hobby.

"I enjoy seeing my kid pull new cards," says Hesse, 32. "He has his own collection and likes opening new packs. But, I’ll hang on to the expensive ones and put them away for when he gets older."

For Christmas, he got Carter three Pokémon cards of Charizard, Blastoise and Venusaur — the 2021 versions of the 1999 cards from the Celebrations: Classic Collection set, PSA graded 10, framed in a shadowbox to hang in his bedroom.

Adam Mahadeo, of Valley Stream, got hooked on Yu-Gi-Oh! when he was 5 years old. Between watching the TV show on channel 11 and his mom buying him packs at Toys R Us, he fell in love with the brand.

"It’s very nostalgic and heartwarming because it brings me back to when I was a kid," says Mahadeo, 27. "I have saved old tins and decks that have been sealed since 2002."

His collection contains 5,000-plus cards and is worth more than $50,000. The crown jewel is a Ghost Rare Stardust Dragon card from the 2008 Duelist Genesis set in near mint condition; it's worth $10,000.

"I enjoy collecting the cards but the friendships I’ve made are more valuable," says Mahadeo. "The Yu-Gi-Oh! community is everything."

By David J. Criblez

david.criblez@newsday.comDavidJCriblez

David J. Criblez is a reporter for Newsday's exploreLI, covering entertainment-related events from local music to stand-up comedy to festivals.